I think the confusion stems from the transaction I made to satoshidice. It says I sent 2 bitcoins to satoshidice but i only actually sent 0.01. Further inspection yields that I actually sent 0.01 to satoshidice and the remainder to address 1EHYT8dFMcDVnkkE9kEoH5T3PBb3bRZdmP. What is that address? Is that one of my addresses that I don't know about?

1 Answer
1

Your Bitcoin wallet can have more then 1 address. In fact the Satoshi client (Bitcoin-Qt) creates 100 addresses from the start.
Both 1HvxJibwAAyVqcNY5GVUWvHSwgYybpRGTp and 1EHYT8dFMcDVnkkE9kEoH5T3PBb3bRZdmP belong to your wallet and thus the total balance you see it correct.

Now to why this did happen.
Your wallet received 2 BTC. When you sent 0.01 BTC to Satoshidice "input" the previous mentioned 2 BTC where used as "output" and had to be spent in its entirety. Because the output was bigger then the input the Bitcoin client sent the difference to a new address, which also belongs to you.